1. Natural Selection

2. —Charles Darwin from "The Origin of Species"
Used by permission of Darwin Day
Celebration (at DarwinDay.org), 2006
I have called this principle, by which each slight variation, if useful, is preserved, by the term Natural Selection.
  —Charles Darwin from "The Origin of Species"
Life Sciences-HHMI Outreach. Copyright 2006 President and Fellows of Harvard College.

3. CHARLES DARWIN – 1809-1882 English
Traveled around the world on the Beagle (ship)
Most of trip was among the Galapagos Islands
Believed that the earth was 6000 years old and that all plants and animals were unchangeable over time
During his travels, he observed many live species, as well as fossils
He did not understand why some species survived while others were going extinct
These ideas went directly against his beliefs

4. Darwin’s Observations
From island to island, he noticed that the species of mockingbird, finches, and other animals varied.
Many of the species Darwin collected had not yet been discovered or classified
Darwin took his collections and drawings home and after reading essays and studies by many other scientists (Gould & Mathus), he developed the idea of natural selection

5. 5 Principles of Natural Selection
Individuals in a population show variation.
Variations can be inherited.
Organisms have more offspring that can survive under normal circumstances.
Variations that increase reproductive success will have a greater chance of being passed on from generation to generation.
A population will slowly change over time in response to the environment.

6. Darwin… By 1840, Darwin had developed the theory of natural selection.
He then published “On the Origin of Species by Means of Natural Selection”
On the last page of this book, he called his theory “evolution”
Evolution is what the process is called ~ natural selection is HOW evolution happens
Another researcher, Wallace, also wrote a similar book at the same time and both books were published and presented to the scientific community.